Distribution of full motion video data has evolved from early television broadcasting to meet viewer demand. Earliest video distribution was by point-to-point wiring between a camera and a video monitor. This was followed by scheduled television broadcasting of programming over the public air waves. In the 1960s, Community Antenna Television (CATV) was chartered to provide off-air television signals to viewers in broadcast reception fringe areas. Later, under FCC regulation, the CATV industry was required to provide local access and original programming in addition to off-air broadcast signal distribution.
In response, several sources of cable network programming were established. Because of the wide bandwidth available on cable television systems, additional channels were available for the new programming. However, programming was generally prescheduled, with the viewer left to tune to the designated channel at the appointed time to view a particular program.
To increase revenues, cable television systems have initiated distribution of premium channels viewable only by subscribers having appropriate descramblers. The subscriber tunes the descrambler to receive a premium channel, descramble the video and audio information and supply a signal capable of reception on a standard television set. Pay-per-view programs, which evolved later, include recently released movies, live concerts and popular sporting events. Subscribers wishing to view a pay-per-view program place an order with the cable operator. At the designated time, the subscriber's descrambler is activated by some control from the cable operator to permit viewing of the pay-per-view programming. However, the subscriber is still restricted to viewing the programming at the scheduled time. There is no capability of delivering programming to a subscriber on demand, that is, immediately or at a subscriber-specified time and date.
More recently, several different wideband digital distribution networks have been proposed for offering subscribers an array of video services, including true Video On Demand service. The following U.S. Pat. Nos. disclose representative examples of such digital video distributions networks: U.S. Pat. No. 5,253,275 to Yurt et al., U.S. Pat. No. 5,132,992 to Yurt et al., U.S. Pat. No. 5,133,079 to Ballantyne et al., U.S. Pat. No. 5,130,792 to Tindell et al., U.S. Pat. No. 5,057,932 to Lang, U.S. Pat. No. 4,963,995 to Lang, U.S. Pat. No. 4,949,187 to Cohen, U.S. Pat. No. 5,027,400 to Baji et al., and U.S. Pat. No. 4,506,387 to Walter. In particular, Litteral et al. U.S. Pat. No. 5,247,347 discloses a digital video distribution network providing subscribers with access to multiple Video On Demand service providers through the public switched telephone network, as described in more detail below.
U.S. Pat. No. 5,247,347 to Litteral et al., the disclosure of which is hereby incorporated in its entirety into this disclosure by reference, discloses an enhanced public switched telephone network which also provides a video on demand service to subscribers over the public switched telephone network. A menu of video programming information is displayed at the subscriber's premises by a set-top terminal and a TV set. The subscriber may transmit ordering information via the public switched telephone network to the independent video information providers. Video programming may be accessed and transmitted to the subscriber directly from a video information provider (VIP) or through a video buffer located at a central office (CO) serving the subscriber.
Connectivity between the central office and the subscriber for transmission of video data is provided by an asymmetrical digital subscriber line (ADSL) system. ADSL interface units at the central office multiplex digital video information with voice information to be transmitted to the subscriber and support two-way transmission between the subscriber's line and the X.25 packet data network of one or more control channels. A complimentary ADSL interface unit at the subscriber's premises separates downstream video control signals and voice telephone signals from the line and multiplexes upstream control signals and voice telephone signals onto the line.
A subscriber can request transmission of video data using a telephone instrument by dialing a Voice Response Unit (VRU) of a video gateway device, through the voice telephone switch and dialing in selection information. Alternatively, the user can access the video gateway device and select a video using a remote control device, the set-top terminal and the control signaling channel through the network. The VIP's equipment identifies the requested title and determines if the title is available.
If the title is found, the corresponding data file is opened and a reserve idle communications port is identified for transmission of the video data to an input node of a digital cross-connect switch (DCS). The video data file is transmitted from the VIP's video storage device, through the DCS, to the designated ADSL interfaces for transmission to the requesting subscriber's premises. The ADSL interface on the subscriber premises demultiplexes the broadband program transmission off of the subscriber loop and applies the digital data stream to a decoder unit in the set-top terminal. The decoder unit decompresses the audio and video data, and converts the digital audio and video to corresponding analog signals. The decoder can supply baseband analog audio and video signals to a television receiver, or these analog signals can be modulated to a standard television channel frequency for use by the television receiver.
While the foregoing patents deal with systems involving wired distribution of the data, entertainment and information within the consumer premises, a number of patents have proposed various schemes for wireless distribution of information of one sort or another.
Robbins U.S. Pat. No. 4,509,211, issued Apr. 2, 1985, describes an electrical system that utilizes an extended infrared radiation link for remote control, such as a TV selector or for data communication.
Williams U.S. Pat. No. 4,882,747, issued Nov. 21, 1989, describes a teleconferencing system including infrared communication apparatus that provides simultaneous video control at a number of remote teleconferencing sites from a central teleconferencing location.
Yasuoka et al. U.S. Pat. No. 4,885,766, issued Dec. 5, 1989, describes a tele-controller system including a control device that receives and stores incoming commands transmitted through a telephone line. The commands are used to operate various apparatuses such as VCR, air conditioner, lamp, etc., at pre-determined times.
Kameo et al. U.S. Pat. No. 4,899,370 issued Feb. 6, 1990, describes an apparatus enabling remote control of electronic equipment such as a VCR through the use of a remote telephone set. A remote controller will provide wireless, line of sight operation of the VCR in response to a signal from the telephone set.
Streck et al. U.S. Pat. Nos. 4,916,532, 5,012,350 and 5,023,931, issued Apr. 10, 1990, Apr. 30, 1991, and Jun. 11, 1991, respectively, describe the transmission of a wireless signal from a VCR to a TV. The output of the VCR is fed into a transmitter and sent to the TV receiver. These patents also describe several prior art arrangements for transmitting a signal from a VCR to a TV set without linking wiring.
Goodman U.S. Pat. No. 5,010,399, issued Apr. 23, 1991, describes a premise video transmission system which uses existing premise telephone wiring to permit transmitting video across the premise without requiring installation of new wires. The patent describes the use of such telephone wiring for transmitting video and control signals without interference with telephone communications. The patent includes a background discussion of prior patents dealing with the problem and points out that not only telephone lines but power lines have been proposed as transmission conduits. However, the patent states that transmission across power wiring is very difficult and, in light of these difficulties, the Goodman patent proposes the use of telephone wiring. The Goodman patent is herein incorporated by reference.
The above discussed media distribution systems provide varied approaches to providing to business and residential premises numerous media services via different types of delivery mechanisms. However, all systems known to have been proposed to date have required a greater or lesser installation of additional signal distribution wiring or cabling in the served premise. In many instances, the installation of such facilities involves a major construction project and significant expense.